Work vehicles, such as agricultural vehicles, earth-moving vehicles, off-road vehicles, loaders and/or the like, often include power shift transmissions equipped with the capability to perform shuttle shifts, wherein the direction of travel of the work vehicle may be reversed without requiring the operator to change gears or use the clutch. For example, to change the direction of travel from forward to reverse, an operator may be simply required to move a shuttle lever disposed within the operator's cab from a forward position to a reverse position.
To increase the productivity and efficiency of work vehicles, efforts have been made to reduce the amount of time required for the transmission to perform a shuttle shift. However, to reduce the time required to perform a shuttle shift, the magnitude of the loads transmitted through the transmission must be increased. For example, to quickly perform a shuttle shift, the inertia of the high speed components of the transmission, as well as the momentum of the work vehicle, must be overcome by the clutches of the transmission within a short period time. This results in significant thermal loads and torque loads being transmitted through the clutches, which can significantly damage the clutches and/or other components of the transmission.
Currently, conventional shuttle methods utilize the clutches associated with the directional gears of the transmission to slow down and reverse the direction of the shafts of the transmission. For example, if a work vehicle is initially traveling in a forward direction, the clutch associated with the forward gear may be disengaged at the initiation of the shuttle shift. The clutch associated with the reverse gear may then be engaged to slow down or stop one or more of the transmission shafts as well as to speed up such shaft(s) in the opposite direction. However, the shaft(s) associated with the forward and reverse gears is typically a high speed shaft(s) that is configured to be driven directly (or indirectly via a counter shaft) by the input shaft. Thus, the clutches for the forward and reverse gears are typically configured to transmit lower torque loads than the clutches associated with the other, lower-speed shafts of the transmission. Specifically, the clutches for the forward and reverse gears are often relatively small and have low torque carrying capacities. As a result, the use of such clutches in performing shuttle shifts can lead to substantial damage to the clutches and/or other components of the transmission.
Accordingly, a system and method for performing shuttle shifts that reduces likelihood of damage occurring to one or more of the components of a work vehicle's transmission would be welcomed in the technology.